How to find compromised email accounts on a Plesk server?

If your emails are bouncing back and IP is getting blacklisted, it is clear your server is used for spamming purpose. To find out if spam emails are sent using a PHP script OR by a client, refer How to find a Spammer on a Plesk Server? Sometimes email accounts are hacked and are used for sending spam email. The header of such emails contain “Network” in the received line instead of the UID of the domain. Below we will see how to trace such accounts. Now, read the mail queue and [...]